Ambient light sensors are in ubiquitous use in mobile devices today. Ambient light sensors measure the brightness of the surrounding environment. They have an optical response closely approximating the optical response of the human eye, and are used to adjust the brightness of the screen based on the brightness of the surrounding environment. In low ambient light, the brightness of the mobile screen is set to low to save the mobile device battery, while in high ambient light the brightness of the mobile device screen is set to high to be visible to the human user. When the ambient light sensor is placed close to an optical element, such as close to the curved edge of the cover glass associated with the mobile device, the ambient light sensor makes inaccurate measurement of the surrounding light because the optical element either focuses incoming light toward or disperses incoming light from the ambient light sensor.